So what exactly did NuForce have in mind when it created the Cube, an almost-perfect 2.3-inch square portable speaker?
It's slightly too big for a prize in a box of Cracker Jack, too small to entertain this weekend's block party and barely heavy enough (5.6 ounces) to hold down a pile of napkins in a summer breeze.
The Cube, obviously, is a speaker. But NuForce, which made its name several years ago with high-end amplifiers costing thousands of dollars before expanding into affordable desktop-audio products, envisioned something grander. The Milpitas, Calif., company calls it a mobile audio center with rechargeable speaker, a USB digital-to-analog converter that bypasses a computer's built-in converter and a headphone amplifier for enhanced private listening.
Good sound in a small form isn't such an outrageous goal anymore with diminutive speakers like the Soundmatter foxL (soundmatters.com) and Logitech's Mini Boombox (logitech.com). The Cube, even with only a singular 1-inch aluminum driver hidden behind a cloth speaker grille, belongs in the same class as those pipsqueak speakers. For its size, this is a glorious little speaker for jazz, folk, chamber music, low-key vocals and anything other than heavy-duty rock and large orchestral works requiring extreme volume and bass.
The Cube is literally plug and play, with no volume controls or on-off switch. It turns on automatically when headphones are plugged in or an iPhone or other portable device is connected to the other minijack receptacle on the Cube's front. Unplug the headphones or portable device and the Cube's red light shuts down, signaling "off." Amplification is minimal, only 3 watts of Class D power, but NuForce gives the Cube some reserve power for short peaks with a "charge pump" circuit that triples the voltage of the lithium-ion battery.
A USB connection to a computer charges the Cube and also enlists the Cube as the computer's default sound device, handling all audio. To the purist, the Cube's immediate attraction will be the USB DAC and the headphone amplifier. A built-in DAC is the favored feature these days in high-end speaker docks like the Bowers & Wilkins Zeppelin and the NAD Viso 1, which bypass an iPhone's own (inferior) converter. In those cases, the iPhone sends a digital signal directly to the dock rather than converting it to a human ear-compatible analog signal detectable. The dock's DAC then handles the analog conversion, producing a higher-quality sound.
With bigger speakers, the difference is usually apparent. But will a built-in DAC make the Cube's 1-inch speaker sound any better? Not to these ears.
NuForce's "audiophile-grade" DAC, connected via USB, made no discernible difference over a Windows laptop's DAC, connected by an analog cable to the Cube. This is an otherwise remarkable 1-inch speaker, but it's just not that revealing.
With the USB connection and headphones, however, the Cube's DAC actually showed a little more body and clarity than an all-analog connection from the laptop to the Cube. Both the Grado iGi earphones and the upscale Bowers & Wilkins P3 headphones were also less fatiguing when using the Cube's DAC.
As a portable speaker, the Cube impressed with the breadth of its sound, the clarity and how loud it could play without distorting. The lithium battery lasts up to eight hours, but NuForce recommends a full charge after each use to maximize battery life.
Side-by-side, I preferred the SoundMatters foxL (now available in its second version), perhaps because it has two speaker drivers about three inches apart and creates a better illusion of stereo sound. The foxL also costs more, $169 for a standard version and $199 with Bluetooth technology for wireless music and speakerphone. The Mini Boom Box plays deeper but sounds somewhat less refined than the Cube and, at $99, also includes Bluetooth.
I'd take the foxL for overall sound, the Cube for headphone listening and the Mini Boombox for the bargain pick (it's often discounted to about $80). It's a great time for tiny speakers.
What: NuForce Cube portable speaker
Cost: $119, nuforce.com
Hot: Great sound for its size, high-grade headphone amplifier circuit when used with Cube's built-in digital-to-analog converter.
Not: Effects of Cube's built-in DAC negligible when listening to speaker, battery must be recharged after each use to ensure long life.